private void renderGL() { glClear(GL_COLOR_BUFFER_BIT); // draw slices if (!syncGLtoCL) { glWaitSync(glFenceFromCLEvent, 0, 0); glDeleteSync(glFenceFromCLEvent); glFenceFromCLEvent = NULL; int errcode = clReleaseEvent(clEvent); clEvent = NULL; checkCLError(errcode); } glBindTexture(GL_TEXTURE_2D, glTexture); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); }